Stuttering is a debilitating communicative disorder, still without a known cause or cure. It is attributed to compromised sensorimotor integration (SMI) in speech, specifically dysfunction in premotor /motor areas associated with producing internal models for speech production and perception and integrating feedback from sensory regions. It is not well understood how stuttering alters SMI for speech perception as there is a paucity of data of time-sensitive measures of SMI in speech / tone discrimination from people who stutter. The goal of the proposed research is to use electroencephalography (EEG) to identify real-time differences in SMI between fluent and stuttering populations in speech / tone discrimination tasks that characterize stuttering. The proposed studies are intended to lay the groundwork for long term research intent on establishing an economical and efficient means of identifying risk for stuttering in young children, as well as identifying functional cortical reorganization related to therapy for stuttering. Specifically, we will measure real-time oscillatoy differences of motor and sensory contributions to SMI between stuttering and fluent speakers that will be identified by measuring changes in spectral power in the alpha and beta bands of EEG mu () rhythms, which we have previously established to index SMI in speech perception. The rhythm is characterized by two distinct bands of energy, one at ~10 Hz and one at ~20 Hz, with changes in spectral power representing sensory and motor contributions to SMI, respectively. It typically is localized to regions of the cortex associated with SMI. Motor (e.g., internal modeling) and sensory (e.g., feedback from auditory regions) activity across the time course of acoustic events will be mapped using event-related spectral perturbation analysis. In two experiments, data will be obtained from adults who stutter and adults who do not stutter and children who stutter and children who have recovered from stuttering. The first experiment will compare discrimination ability in addition to the strength and timing of motor and sensory contributions to SMI in quiet and noisy syllable and tone discrimination tasks between the two groups of adults. The second experiment will compare discrimination ability in addition to the strength and timing of motor and sensory contributions to SMI in speech discrimination tasks and comparable tone discrimination tasks in children who stutter and those who have recovered from stuttering. Successful completion of this project will impact the understanding of the neuropathology of stuttering by providing a sensitive neural marker of the disorder, identifiable via speech perception. It will provide the impetus for developing translational long-term studies designed to further assess the use of this protocol as an economical and efficient litmus test for stuttering in young children. It is the first step in developing a tool to predict risk of stutterig and persistence versus recovery from developmental stuttering in young children. In addition, it supplies an outcome measure of functional cortical re-organization following therapy for persistent stuttering.